#include<iostream>
#include<string>
// #include"fenshu.hpp"
using namespace std;

char fuhao[] = {'+','-','*','/'};
// 2 3 4
// 式子随机长度
int rand_len(){
    return rand()%3+2;
}
char rand_fuhao(){
    
    return fuhao[rand()%4];
}

string bad_generator(){
    
    srand(time(0));
    int len = rand()%3+2;
    string result="";
    for(int i=0;i<len;i++){
        fenshu a;
        result+=a.to_string();
        if(i!=len-1){
            result.push_back(fuhao[rand()%4]);
        }
    }
    // cout<<result<<endl;

    return result;
}